Re: Optimizer oddness, possibly compounded in 8.1 - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Optimizer oddness, possibly compounded in 8.1
Date
Msg-id 2954.1133538168@sss.pgh.pa.us
Whole thread Raw
In response to Optimizer oddness, possibly compounded in 8.1  (Philip Warner <pjw@rhyme.com.au>)
Responses Re: Optimizer oddness, possibly compounded in 8.1  (Philip Warner <pjw@rhyme.com.au>)
List pgsql-hackers
Philip Warner <pjw@rhyme.com.au> writes:
> The optimizer seems to want to use sequential scans on inherited tables
> when crossed with another table, as the following seems to demonstrate:

Is it intentional that your test case omits an analyze on t2?  Coz when
I add that, I get the same plan you show for 8.0.  Without the knowledge
that t2 is small, that plan is not a good choice.

(The larger point that joins of inheritance unions aren't well-planned
is true, but it's always been true...)
        regards, tom lane


pgsql-hackers by date:

Previous
From: Jaime Casanova
Date:
Subject: Re: Graphics in postgress using GTK
Next
From: "luckyghio@katamail.com"
Date:
Subject: postgres questions (semi-joins, algebraic space)